Process for composite desulfurization of molten iron

Abstract

The invention relates to desulfurizing process of molten iron, which belongs to metallurgy area of iron and steel. The invention molten iron double desulfurization method adopts rotary-type sprayer with agitator on the nozzle. Rotating spray of nozzle cooperates with agitation of agitator to desulfurize molten iron, in which rotary-type sprayer jets desulfurizer into the molten iron while agitator stirs the molten iron. Meanwhile, another desulfurizer CaO is released to molten iron from the top of hot-metal bottle or sack. CaO has the function of desulfurizating and thickening desulfurizing slag, which saves densifier compared with present technology. When sprayer jets desulfurizer, nitrogen is adopted as carrier gas and dense-phase is adopted to transport desulfurizer, which comprises anyone or combination of more than two of Na2O, CaO, CaC2 and Mg and takes the formation of powder. This invention has the following properties: perfect effect of desulfurizating (sulfur content of molten iron can drop to <=0.005% after desulfurizing process), low temperature drop (approaching <=1 DEG C / min), low cost of desulfurizer (0.2-0.5kg / tmolten iron) and good comprehensive economic effect (especially adapting to molten iron desulfurizating in mini-steel plant).

Description

technical field

[0001] The invention belongs to the field of iron and steel metallurgy and relates to a molten iron desulfurization process. Background technique

[0002] In the prior art, hot metal desulfurization is a widely used process. With the gradual promotion of molten iron desulfurization technology in my country, various desulfurization technologies have also been adopted one after another. From the desulfurization of iron gutters to desulfurization of torpedo tanks or ladles, desulfurization agents have developed from soda, calcium carbide powder, and lime to pure magnesium. The way of adding the agent has been developed from artificial and launder to spray gun injection, and finally formed two methods: stirring method and injection method. However, small-capacity molten iron ladles (or tanks) are commonly used in small and medium-sized blast furnaces. The above two methods alone cannot meet the requirements of molten iron desulfurization. Slagging before and aft...

Examples

Embodiment Construction

[0034] According to the composite desulfurization method of the present invention, a rotary spray gun with an agitator is used to desulfurize 4 cans (bags) of molten iron.

[0035] Drive the molten iron tank (bale) to the injection desulfurization station (the positioning device is installed on the railway), the system starts to run, the rotary spray gun starts to input the desulfurizer according to the injection system program, and simultaneously stirs and injects to reach the calculated After blowing the amount, the gun is automatically lifted to stop stirring and blowing, and the desulfurizer put in from the top of the ladle (tank) is put into molten iron from a meterable hopper.

[0036]The chemical composition of the 4 cans (packages) of molten iron before treatment is shown in Table 1. The types of desulfurizers, composite desulfurization methods and desulfurization cycles used in the 4 packages (pots) of molten iron are shown in Table 2. The desulfurization agent spraye...

technical field

[0001] The invention belongs to the field of iron and steel metallurgy and relates to a molten iron desulfurization process. Background technique

[0002] In the prior art, hot metal desulfurization is a widely used process. With the gradual promotion of molten iron desulfurization technology in my country, various desulfurization technologies have also been adopted one after another. From the desulfurization of iron gutters to desulfurization of torpedo tanks or ladles, desulfurization agents have developed from soda, calcium carbide powder, and lime to pure magnesium. The way of adding the agent has been developed from artificial and launder to spray gun injection, and finally formed two methods: stirring method and injection method. However, small-capacity molten iron ladles (or tanks) are commonly used in small and medium-sized blast furnaces. The above two methods alone cannot meet the requirements of molten iron desulfurization. Slagging before and aft...

Examples

Embodiment Construction

[0034] According to the composite desulfurization method of the present invention, a rotary spray gun with an agitator is used to desulfurize 4 cans (bags) of molten iron.

[0035] Drive the molten iron tank (bale) to the injection desulfurization station (the positioning device is installed on the railway), the system starts to run, the rotary spray gun starts to input the desulfurizer according to the injection system program, and simultaneously stirs and injects to reach the calculated After blowing the amount, the gun is automatically lifted to stop stirring and blowing, and the desulfurizer put in from the top of the ladle (tank) is put into molten iron from a meterable hopper.

[0036]The chemical composition of the 4 cans (packages) of molten iron before treatment is shown in Table 1. The types of desulfurizers, composite desulfurization methods and desulfurization cycles used in the 4 packages (pots) of molten iron are shown in Table 2. The desulfurization agent spraye...